Traveling impression roller means for time print wheels

ABSTRACT

The present time stamp eliminates the usual hammer and solenoid with their impact noise. Instead, a carriage is mounted for reciprocating travel along the print wheels, and an impression roller carried by the carriage serves to press successive parts of a document against the print wheels. The desired print is thus obtained by means of a quiet rolling action rather than by a noisy hammer impact. There is smooth acceleration and deceleration of the carriage, thereby further avoiding noise and vibration. There are print wheels for date, month, year and the time in hours and minutes. Most of the print wheels are moved by pawl and ratchet mechanism. A timing motor drives a cam and cam follower to operate the pawl, and the cam configuration causes smooth acceleration and deceleration of the pawl movement, which again contributes to quiet operation. The time print wheels are provided with separate readout discs. These are made of sheet material and are progressive in diameter to expose readout numerals on the outer faces of the discs near their periphery. The time print wheels have concentric hollow shafts each extending axially to its readout disc. Additional print wheels print the date, the month, and the year.

United States Patent [72] Inventors Gerhard A. Foerster 3,353,480 11/1967 Lowell et al. 101/91 Woodbridge; 3,363,547 1/1968 Thut et a1. 101/45 Walter Wolog, New Haven; Louis Cetran, 3,363,550 [/1968 Kruger ll/269 e s William Ryan, Bethany, all FOREIGN PATENTS o onn.

. 823,318 1/1952 German [211 APPI- 777,218 858.324 12/1952 German; [22] Filed Nov. 20, 1968 p d D 7, 1971 Primary Examiner-William B. Penn 73 i i, Mi Corporation Anorney.lames and Franklin New Haven, Conn.

- ABSTRACT: The present time stamp eliminates the usual 54 TR vEu pRE $1o ROLLER MEANS FOR hammer and solenoid with their impact noise. instead, a car- E PRI T WHEELS riage is mounted for reciprocating travel along the print 1] Ch 19 1: wheels, and an im ression roller carried by the carriage serves s. n; 8 P 2 CI v to press successive parts of a document against the print [5 l o o a I n I I I u a u l a n 1 a I Q a s I Q I a v u I n a u a 7 101,45 346/80 rolling action rather than by a noisy hammer impact. There is [5 I] ll!!- CI t. B41 3/02, smooth acceleration and deceleration of the carriage thereby j I Gold 5/20 further avoiding noise and vibration. There are print wheels Field of Search... 101/45, for date, month yea. and tin, me in hours and minutes Most a Y 1 348/ 81 of the print wheels are moved by pawl and ratchet mechanism. [561 m CW .3?"ifd'lfiflffi finfillfii ZZILSEZ LZZQaZZZiZIZJES UNITED T T PATENTS 2nd deceleration of the pawl movement. which again con- 923,085 5/ 1909 Smith tributes to quiet operation. The time print wheelsare provided 1,726,541 29 C le -L- l0l/274 X with separate readout discs. These are made of sheet material 5 2/1933 h lps 135 and are progressive in diameter to expose readout numerals 2,019,301 V Ffidlu on the outer faces of the discs near their periphery. The time 2.0 .3 5 1937 88 el l0l/233 X print wheels have concentric hollow shafts each extending axi- 2.l26.347 8/1933 Rullimah---- /2.37 X ally to its readout disc. Additional print wheels print the date, 2,425,249 8/1947 Lacy-Hulbert 101/35 the month, and the year. 3,037,447 6/1962 Gonzalez et al. l0l/9l 166 I78 /52 1.96 2, ss I94 42' :l 70 I n 3; l 6 5 i Z /40 l 50 E Z8 J 144 :1 L 2 '1 I i I i 26 8% i| I g; l2 h w M .1

79 J e Z! l PATENIEDDEB 7197i SHEET 2 OF 7 1 L z 2 a i: Ewan a E 9 an r om R, N M .V m m We L m Ill v f m Mi I ["lzN'l'U/(S GERH'ARD A.FOERSTER WALTER L.WOLOG LOUIS CETRAN WILLIA P. RY N 44 1 ATTORNEYS 9 HY'Z PATENIEDDEB Han Y 31626463 'sumvnr? I Fla. /9

' INVI'IN'I'URS GERHARD A; FOERSTER WALTER LWOLOG LOUIS CETRAN WILLIAM P. RYAN :IIY

% M a I A TORNEYS TRAVELING IMPRESSION ROLLER MEANS FOR TIME PRINT WHEELS Devices for stamping time and date on letters and documents are already known. These usually employ a solenoid and hammer action for the printing operation, and are therefore noisy. The devices are commonly called time stamps," because of the stamping action. The print wheels are advanced intermittently by appropriate pawl and ratchet mechanism. This may be operated by a clock motor, usually a small synchronous electrical motor. The pawl and ratchet mechanism, often operated by a solenoid, causes a clicking sound. The prior devices have also been relatively large and cumbersome.

There is need for a time stamp which is compact and silent, and therefore suitable for use on a desk top or table top, in executive and professional offices, hospitals, schools, and the like.

Our present time stamp eliminates the usual hammer and solenoid with their impact noise. Instead, there is a carriage mounted for reciprocating travel along the print wheels, and an impression roller carried by the carriage serves to press successive parts of a document against the print wheels. The desired impression is thus obtained by a rolling action rather than by hammer impact. (However, the commonly used term stamped is retained herein for convenience). The document is instantly released at the end of the print travel and during return of the carriage to initial position. A motor and reduction gearing preferably turn a crank to drive linkage which is connected to the carriage, and the crank action provides a smooth acceleration and deceleration of the carriage, thereby avoiding noise and vibration. More specifically, there are rollers on which the carriage rides during its print travel. The starting end of the rails slope upward to raise the impression roller to desired height. At a point beyond the print travel the rails terminate to cause dropping of the carriage away from the print wheels. The rails are arranged to permit return movement of the carriage at a lower level.

With roller printing, compared to impact printing, there is a momentary delay before the document is freed for removal from the machine. It is therefore desirable to speed the printing action. For this purpose we provide resilient means connected to the carriage in such fashion that it assists the printing travel of the carriage and resists its return movement. During the return movement energy is again stored in the resilient means. A slower return movement is unimportant because the stamped document has already been released for removal. Such resilient means accomplishes the desired purpose without enlargement of the driving motor.

lnking is provided by means of an ink ribbon extending from a supply roll to a takeup roll. The impression roller moves in the direction of the axis of the print wheels whereas the ink ribbon extends in a direction transverse to the axis of the print wheels, the ribbon being as wide as the entire assembly of print wheels for printing day, month, year, hours and minutes. Ribbon feed is provided.

The print wheels are moved by pawl and ratchet mechanism, and for this purpose a timing motor drives a cam to cause a cam follower to operate the pawl at one minute intervals. The cam configuration is such as to cause smooth acceleration and deceleration of the pawl movement, which again contributes to quiet operation. A first printing wheel, numbered from through 9, prints the minutes, and an adjacent printing wheel, numbered 0 through 5, prints the tens of minutes. Another printing wheel, numbered from 0 through 23, prints the hours of the day.

Each printing wheel has its own ratchet wheel. The wheels have like diameter, and therefore the numbering 0 through 9 may be repeated after half the periphery, and the numbers 0 through may be repeated three more times, occupying only the fourth of the periphery. This is consistent with the need for a print wheel large enough for the 24 hours per day, using the continental system, and for 31 days in a month. (The hours wheel could read I through'IZ twice, but this is less convenient, because of the resulting ambiguity at between AM and PM.)

The time print wheels are provided with readout discs. These are made of sheet material and are progressive in diameter to expose readout numerals on the outer faces of the discs near their periphery. The endmost print wheel is secured to the readout disc of largest diameter. The next printing wheel has a hollow shaft extending axially through the endmost wheel and its disc to the readout disc which is next smaller in diameter. The next printing wheel has a hollow shaft of smaller diameter extending through the other printing wheels and discs to the smallest readout disc. The operator reads the time in hours and minutes in normal fashion through a horizontal window at the front end of the device.

Additional print wheels print the date, the month and the year. The date print wheel requires numerals I through 31, leaving no room for readout numerals, and is therefore given an associated readout wheel. The month and year print wheels have ample space between the print numerals for readout numerals located directly on the periphery of the print wheels. A window at the top of the housing serves for visual display of the day and month readout. A readout for years is superfluous.

Insertion of a document starts the travel motor, and completion of the cycle is assured even though the document is removed during the cycle. Repeat operation is prevented, even if the document is left in the machine.

The foregoing and additional features are described in the following detailed specification, which is accompanied by drawings in which:

FIG. I is a perspective view showing the exterior of a time stamping device embodying features of the invention;

FIG. 2 is a vertical section taken approximately in the plane of the line 2-2 of FIG. I;

FIG. 3, a horizontal section taken on the line 3-3 of FIG. 2, I

is essentially a plan view with the top of the housing removed;

FIG. 4 is a transverse vertical section taken approximately on the line 4-4 of FIG. 3;

FIG. 5 is a transverse vertical section taken approximately on the stepped line 55 of FIG. 3;

FIG. 6 is a fragmentary vertical section drawn to enlarged scale, and taken approximately on the stepped line 6-6 of FIG. 3;

FIG. 7 is a plan view explanatory of the trigger mechanism;

FIG. 8 is an elevation of the trigger and switch mechanism;

FIG. 9 is an elevation of a multiple pawl used for ribbon feed;

FIG. 10 is a bottom view of the same;

FIG. 11 is an end view of the multiple pawl of the timing mechanism;

FIG. I2 is a side view of the same;

FIGS. 13 and I4 are front and end elevations respectively of a fixed inscription plate mounted in the machine;

FIG. 15 is a plan view of a modified trigger mechanism;

FIG. 16 is a vertical elevation looking from the left of FIG. 15; I

FIG. 17 is a vertical elevation looking toward the right of FIG. 16;

FIG. 18 shows a switch carrier plate; and

FIG. I9 is an elevation showing how the device may be hung on a wall, instead of resting on a table.

Referring to the drawing, and more particularly to FIG. I, the device 12 has a widely open throat 14 into which a document which is to be time stamped is readily slid. The stamped information may be printed either horizontally or vertically according to which way the document is inserted. The document rests on a thin resilient metal sheet 16 which is secured at its forward end, as by rivets 18 or other means, and the rear end of which is cut away for the printing operation. The horizontal window 20 provides a visual display of the time then set on the print wheels. The top window 22 permits visual inspection of the reading of the print wheels for the day, which is usually. sufficient, but the month and year can be shown if desired.

' The inserted document is quietly stamped by means of a roller action in contradistinction to an impact or hammer action. Referring to-FIGS. 2 and 4 there is a carriage 24, the forward end of which rests on antifriction rollers 26. The carriage carries a somewhat elevated impression roller 30. When the carriagemoves rearward, or to the right as viewed in FIG. 2, the rollers 26 ride up the sloping parts 32 of a pair of spaced rails 34. This raises the impression roller 30 so that it bears upwardly on the paper to be stamped. The roller 30 is preferably carried by a leaf spring 31 so that it can yield for a thicker document being stamped. The plate 16 is cut away beneath the print wheels, as shown in FIGS. 2 and 4, for a rolling action directly on the part of the paper being printed. An ink ribbon is disposed above the paper and beneath the print wheels. It is masked by a plate therebeneath, this plate defining the top of the throat, and having an opening for the print area.

The rails 34 are not fixed, the rear ends being pivoted at 36 on pivot pins carried by brackets 38 fixed on the base 40 of the machine. The forward ends of the rails are urged downward by light coil springs 42 at the pivot pins 36.

Referring now to FIG. 6 the tops of the rails 34 are terminated or interrupted as shown at 44, at which point the support or lift rollers 26 descend as suggested by the downwardly pointing arrow 46 at the rearward or broken line position 26' which is before descent of the rollers. At this time the impression roller is at 30' where it has completed its printing travel beneath the series of print wheel thereabove. n descent of rollers 26' and 30' the document is instantly and fully released for removal.

During the return movement the lift rollers 26 ride beneath the rails 34, and finally engage the sloping forward ends 32 of the rails 34, as shown by the broken line position 26" in FIG. 6. This raises the rails until the lift rollers move beyond the ends of the rails, which then return to the normal position shown in solid lines. The rest position of the rollers 26 and 30 is shown in solid lines.

The carriage travel is provided by a motor 48, best shown in FIGS. 2 and 3. The motor drives a worm 50 meshing with a worm gear 52. Referring now to FIGS. and 6, worm gear 52 turns a crank 54 having a crank pin 56. The latter is received in the slot 58 of a slotted arm 60, the upper end of which is pivoted on a fixed pin 62. The lower end is pivotally connected to the carriage by a pin 64. In FIG. 6 arm 60 is moved from the solid line position to the broken line position 60', thereby pulling the carriage 24 from the solid line position to the broken line position 24'.

The arm 60 is preferably a reversely folded or double member as is best shown in FIG. 5, it comprising spaced arms 60 and 66 integrally joined at 68. The pivot pin 62 passes through both arms, and is held in fixed supports 70. The lower ends of both arms 60, 66 are connected to the rear end of the carriage 24 by means of the pin 64 which is secured in the downturned sidewalls 72 of the carriage. These sidewalls also carry the lift rollers 26 previously referred to.

The crank action has the advantage of providing a smooth acceleration and deceleration of the carriage 24, thus operating with minimum vibration and noise. Fast travel of the impression roller 30 is desirable in order to promptly release the document for removal. For this purpose the carriage is urged rearward by resilient means, in this case a long pull spring 74 which is shown in its stretched condition in FIG. 2. The spring urges the carriage to the rearward position shown in FIG. 6. The return movement stretches and stores energy in the spring. This tends to somewhat slow the return movement, but that is of no consequence because the document has already been released by the drop of the carriage instantly after completion of the working or printing movement. In this way the travel motor 48 may be kept small, and yet provides the desired rapid printing movement.

Considered more specifically, during the first 42 rotation of the crank 54 the travel motor 48 accelerates to full speed, and the impression roller 30 rises. The next 58 rotation causes printing. When the crank approaches I00 rotation, the carriage lift rollers 26 drop through the rail openings to the lower level, thereby releasing the stamped document. 23 of rotation is allowed for this transfer, and the return stroke begins with the rollers 26 rolling on the lower level, and lifting the pivoted rails 24 near the end of the return travel, until the rails again drop behind the rollers. The switch latch (described later) is released a bit ahead of time, this being made up by rotary inertia of the rotating mechanism. The power spring 74 is extended during the return stroke, storing energy for the next cycle. The above specified angles are given by way of example, and are not intended to be in limitation of the invention.

When a document is inserted in the throat of the machine, as shown by document 76 in FIG. 2, it deflects a trigger 78 disposed in its path. Referring now to FIG. 3, the document moves the trigger rearward from position 78 to position 78'. This closes a switch 80 which energizes the travel motor 48. The trigger linkage is latched to hold the switch 80 in closed condition during the return movement of the carriage, even though the document has already been removed.

The latch mechanism is separately shown in FIGS. 7 and 8. The switch 80 (FIG. 8) has an operation pin 81 which is depressed by a tab 82 on an upright arm 83 fixedly pivoted at 84. Referring to FIG. 7, trigger 78 is one arm of an angle lever pivoted at 85. Its other arm 86 latches or interposes the lower end of arm 83 with the switch in open position, the switch being normally closed. On insertion of the document the interposer 86 frees arm 83, which moves to the left, permitting switch 80 to close.

Referring now to FIG. 8, the worm gear 52 and/or the crank carried thereby having a camming pin 87, and near the end of the cycle this bears against the tab 88 and moves arm 83 back to latched position, thereby deenergizing the motor. Trigger 78 is biased to forward or latching position, as by means of scissor spring 89 (FIG. 2).

Even in the event the document is held in the machine for an excessive time, the cycle is not repeated. For this purpose an auxiliary latch 90 (FIG. 7) is provided, also pivoted at 85. It is lightly biased clockwise as viewed in FIG. 7, but is normally held back by a tab 91 on arm 86 bearing against a projection 93 on arm 90. However, if the trigger 78 is held back by a document, the arm 90 is free to move clockwise when arm 83 is moved back by the camming' stud 87 (FIG. 8) on worm gear 52 at the end of the first cycle, as previously described, and the arm 83 then is again latched with the switch in open position, by arm 90. When trigger 78 is released by removal of the document, the arm 86 takes over the latching function from arm 90, the parts then being restored to the position shown in FIG. 7.

It should be noted that detent step 95 in auxiliary latch 90 is a little further to the right than the detent step 97 in arm 86. This prevents arm 90 from following arm 86 when the document is first inserted in the machine.

Ink is provided by an ink ribbon, and referring to FIG. 4, the ink ribbon 92 extends from a supply roll mounted at 94 to a takeup roll mounted at 96. When housed as here shown, rotation of the housings is prevented, as by means of lugs 98. Ink ribbon 92 extends transversely of the axis or shaft 100 which supports the print wheels. The ink ribbon has been omitted in some figures of the drawing, for clarity, but is shown in section at 92 in FIG. 6, where it will be seen that the ink ribbon is as wide as or wider than the assembly of print wheels. In the present case it is 1% inches wide. The takeup reel is turned a very small fraction of a revolution at intervals in order to supply a fresh part of the ribbon. In FIG. 5, ratchet wheel 102 is moved one tooth for each printing operation. There are two adjacent coaxial ratchet wheels, and the first has an extra deep notch between teeth, commonly called a deep tooth, as shown at 104. This permits another and shorter pawl 106 to engage the second ratchet wheel, which then is moved one tooth, and that ratchet wheel is connected to the takeup reel to cause a slight feed of the ribbon. Pawl l08'is pivoted at 110 at an angle lever 112, the other arm 114 of which is moved by any suitable means, for example the camming stud 87 carried by the crank and the worm gear 52 as previously described. The pawl 108 is separately shown in FIGS. 9 and 10, referring to which its rear end is reversely bent to provide spaced bearings 116 and 118, which receive the pivot pin 110 previously mentioned. The shorter pawl finger is shown at 106, and the longer pawl finger at 120. In FIG. the pawl is inverted compared to its position in FIG. 5. In that figure it will be seen that the pawl is both biased downward and is driven by a pull spring 122. Once each cycle the pawl is moved back by angle lever 112 thereby stretching the spring 122, and again released to move the first ratchet wheel 102 a single tooth. Reverse movement of the ratchet wheels is prevented by leaf springs 124 (FIGS. 5 and 2) acting as check pawls. In the present case the ratchet wheel 102 has 30 teeth, and after 30 printing cycles, the adjacent ratchet wheel 126 (FIG. 2) is moved one tooth. Wheel 126 has a square or other noncircular shaft mating with the shaft of the ink ribbon spool, and so turns the spool a short distance corresponding to one tooth of the second ratchet wheel 126. The timing motor is shown at 132 in FIG. 3. It may be a synchronous motor of the type used in electrical clocks, and after gear reduction, drives its output shaft 134 one revolution per minute. Referring to FIG. 5 shaft 134 turns a cam 136, engaging a cam follower 138, mounted on a pawl arm 140, which oscillates about shaft 100 of the print wheels. Am 140 is in the form of a broad yoke integrally connected at a top portion 142, and wide enough to straddle the entire print wheel assembly. The other arm 144 of the yoke is shown in FIGS. 3 and 4. As viewed in FIG. 5 the pawl arm is urged in counterclockwise or feed direction by means of a return spring 146.

The cam 136 is so contoured that the pawl movement in both directions is smooth and therefore quiet and vibrationless. As the round cam follower 138 starts to slide around the high point of the cam, it exerts a forward pressure on the cam face, thereby removing all gear backlash within the timing motor. The slow rotation of the cam and the tailored shape on the downslope of the cam controls the speed of the cam follower and the attached pawl 148 to provide a smooth acceleration and deceleration, resulting in a noiseless advance to the next minute reading. The power needed in the spring 146 is restored during the subsequent gradual rise of the cam 136. Pawl 148 is pivoted on a pin 149 and is biased downward by a spring 151.

The pawl itself is of a known type in which one integral pawl body I48 (FIGS. 3, I1, and 12) has a number of fingers, one for each ratchet wheel. These fingers have teeth of progressive length, as shown by the teeth I50 and 152 in FIGS. 4 and 11, or the teeth 154 and 156 shown in FIGS. 5 and 11. FIGS. 4 and 5 also show the holding or check pawls 158 mounted on a spindle 160, and urged downward as by means of the fingers of a leaf spring 162. FIG. 3 shows the six individual holding pawls 158 mounted on a common spindle I60, and also shows how the spring 162 is slotted to provide six spring fingers, one for each check pawl. Because of the downward pressure of the springs the multiple pawl may rest in a round trough, instead of receiving a pin.

Referring to FIG. 6, the first printing wheel 164 is numbered 0 through 9 for minutes, and is formed integrally with and is driven by a ratchet wheel I66. The next printing wheel 168 is numbered 0 through 5 and prints l0s of minutes. It is formed integrally with and driven by a ratchet wheel 170. The next printing wheel 172 is numbered 0 through 23 for the hours of the day, and also has an integral ratchet wheel 174. The extra printing projection at 176 prints a semicolon, which then appears between the hours and minutes. The range of reading is from 0:00" (meaning midnight) to 23:59"

The next number wheel I78 prints the year in abbreviated form, e.g. 68, 69," etc. This is set manually once a year, but the wheel 178 is preferably provided with the usual integral ratchet wheel 180, for reception of one of the check pawls 158 previously mentioned, thus fixing the setting of the wheel. The next wheel 182 indicates the month with appropriate abbreviations such as Jan., Feb.," etc. It is integrally formed with a ratchet wheel 184. The final print wheel 186 prints the day of the month ranging from 1 to 31. and has an integral ratchet wheel 188-. The raised lettering on the print wheels is in reverse or mirror image, so that the complete printing reads in desired direction and sequence, e.g. l4 Jan. 68 11:49."

The numbered wheels are preferably provided with a readout to check the setting and to facilitate a change of setting. Referring to FIG. 6 the time readout is displayed on readout discs made of sheet material and varying progressively in diameter as shown at 190 I92 and 194. The hours wheel 172 has a hollow shaft 196 around the fixed spindle 100, and disc 190 is secured to the outer end of hollow shaft 196. Print wheel 164 has a hollow shaft 198 disposed around the hollow shaft 196, and carrying the disc 192 at its outer end. Print wheel 164 is rotatable around the hollow shaft 198 and carries the largest readout disc 194. This provides a reading in desired sequence, that is, hours followed by minutes, as will be seen in FIG. 4 by the reading "0:00" in the horizontal window 20. The window is remote from the pawl arm 144. The readout numerals are displaced from the print numerals.

Readout for date is desirable. Readout for month and year is not needed but may be provided. Reverting to FIG. 6, the month wheel 182 requires only l2 positions and therefore has ample room between the raised printing characters to receive a readout indication in correct lettering, it being recalled that the print characters are in reverse or mirror image, and therefore difficult to read. Moreover, the readout months are displaced 180 from the corresponding print months on the same wheel. The wheel should be deeply recessed if used for readout, to avoid contact with the ink ribbon.

Similar remark would apply to the print wheel 178 for the year, the number of years being arbitrarily chosen and preferably is ID years. A readout may be provided between characters, if desired, displaced l80, and deeply recessed, as in the case of the month wheel. The window would then be enlarged to expose the year readout. The housing is openable for access to change the wheels manually.

The datewheel 186 requires numbering from 1 through 31, and this does not provide room for readout numerals between the printing numerals. Instead, a separate readout wheel is provided shown at 200. This is secured to the print wheel 186 (FIG. 6) and carries the same 31 numbers, as shown in FIGS. 2 and 3. Because the'print wheels print at the bottom while the readout window 22 (FIG. 1) is at the top, the readout numerals are displaced [80 from the corresponding print numerals. The month wheel 182, like the year wheel 178, must be moved manually. The date wheel 186 is moved automatically from day to day, but it presupposes 3| days in a month, and therefore requires manual adjustment for those months having 28 or 30 days.

The pawl 148 has four fingers -156 (FIG. II) of four different height levels. The pawl finger 150 at lowest level engages the minute wheel ratchet 166. At l0 minute increments, a deep tooth allows the first pawl finger 150 to drop to the next lower level, with finger 152 engaging and advancing one tooth of the 10 minute ratchet wheel 170. When the 59th minute is reached, a deep" tooth in wheel as well as wheel 166 allows the pawl to drop to the next lower level and finger 154 engages and advances the hour wheel 174 one tooth. At 23 HOURS AND 59 minutes there is a deep tooth on wheel 174 and the pawl again drops to the lowest level, so that finger I56 engages the date ratchet wheel I88, and moves it to the next date. The first three time wheels will then show 00 hours, 00 minutes, which means midnight. All of the wheels are held in proper position by the six detent pawls 158.

The pawl movement should be greater than that required to move the date wheel one day, and less than that required to move the date wheel 2 days. This limitation on the pawl travel affects the other print wheels. For example, the minutes print wheel 164 preferably has its numerals 0 to 9 two times around the wheel. The 10's of minutes print wheel 168 has its numerals 0 through 5, four times around the wheel. The hours wheel 172 has numerals through 23 once around the wheel. The months and year wheels 178 and 182 have characters only once around the wheel, but they are moved manually.

The operation of the pawl with fingers of progressive height is known, and requires no further detailed description. The pawl finger for ratchet 166 is the longest, and holds the other fingers away from their ratchet wheels until the numeral 9 where there is a so-called "deep tooth" (actually a deep root or a space between two teeth) which permits lowering of the pawl until the next shorter finger engages the ratchet wheel 170, which in turn limits the drop of the pawl until ratchet wheel 170 has a deep tooth, and so on. Wheel 166 has two deep teeth diametrically related, and wheel 170 has four deep teeth. Wheel 174 has one deep tooth.

The pawl fingers may differ not only in height but also in displacement around the wheels, as will be seen in FIG. 11.

In addition to printing of time and date, the device is also arranged to receive a fixed printing plate which prints another line, say one-half inch from the date and time stamp. This inscription plate may identify a company, or a division of the company, or an individual. Such an inscription plate is shown at 160 in FIG. 4 the lettering being located at 162, which is about one-half inch from the date and time line. The inscription plate is secured to the main body or frame of the machine by a pair of screws indicated at 164. The plate 160 is located above the ink ribbon 92, and its lettering is in the same horizontal plane as the bottom of the print wheels.

The inscription plate is shown separately in FIGS. 13 and 14, the plate 160 having type characters at 162, and being secured by screws passing through the holes 166.

In FIG. 4 the impression roller is shown offset to the right, compared to the time stamp line, and the fixed name plate is mounted to the right, about in line with the trigger 78. There is no interference because the plate is above the trigger 78 and above the ink ribbon 92.

The trigger mechanism so far described works successfully and is independent of gravity. However, the final segment of rotation of the worm gear 52 requires brief rotation of the motor 48 and worm 50 by inertia after power to the motor has been cut off. This may fall short, as in the event the power supply voltage to the motor happens to be low when cut off.

An improved trigger mechanism may be described with reference to FIGS. 15, 16 and 17. In those figures the worm gear 52 with its crank pin 87 corresponds to the like numbered parts previously described. The trigger wire 200 corresponds generally to but is longer than the trigger arm 78 shown in FIG. 7, and is connected to and moves a primary interposer 202 which corresponds to the part 86 in FIG. 7. This is accompanied by a secondary interposer 204 which corresponds to the part 90 previously described. The trigger sensor and reset arm 206 corresponds to the arm 83 in FIG. 8. The precision snap action switch 208 corresponds to the switch 80 previously described, and similarly has a spring-loaded plunger 210 to operate the same, but there is a difference in that switch 208 is not fixedly mounted, but instead is carried by a switch carrier plate 212 (shown separately in FIG. 18), this being pivoted at 214 like the trigger reset arm 206 which is also pivoted at 214. The switch carrier plate 212 has a long tab 222 and a short tab 224, and is urged clockwise by a pull spring 216 which tends to move plate 212 and switch 208 toward the left as viewed in FIG. 17. The plate is stopped by the long tab 222 bearing against reset arm 206. The holes 213 (FIG. 18) are for mounting the switch 208.

The operation is as follows: The spring-loaded plunger 210 in switch 208 urges the tab 211 of the trigger reset arm 206 in clockwise direction (FIG. 17), but the lower or sensor end 218 of reset arm 206 is held back by the primary interposer 202 (FIG. When a document is inserted it bears against the upright part 220 of the trigger wire 200 (FIG. 15) and deflects the wire clockwise as viewed in FIG. 15, and the switch plunger 210 thereupon moves the tab 211 and the reset arm 206 in clockwise direction, as viewed in FIG. 17, its lower sensor end 218 sliding along the side of. the latch 202 until the switch contacts close, thus starting the motor, not shown here, but the same motor 48 driving a worm 50 as shown in FIG. 2 and previously described, the said worm meshing with the same worm gear 52 here shown. The motion of the sensor end 218 of reset arm 206 is limited by its tab 219.

As the motor drives the printing mechanism through its cycle, causing movement of the carriage 24 and its impression roller 30, the pin 87 carried by the worm gear 52 slidingly engages the long tab 222 of the switch carrier plate 212 near the end of the printing cycle.

During the next 50 of rotation of the worm gear the pin 87 bearing against the long tab 222 moves the switch carrier plate 212 with the switch 208 in counterclockwise direction, and carries the trigger reset arm 206 along with it by means of a second smaller tab 224 until the lower or sensor end 218 of the reset arm clears the front edges of the interposers 202 and 204.

If the document has been withdrawn before completion of the cycle, the torsion spring 226 moves the interposer 202 with its trigger 200 in counterclockwise direction (FIG. 15), thereby interposing and blocking the rigger reset arm.

If the document remains inserted instead or being removed, the torsion spring 226 moves the secondary interposer 204 in clockwise direction until its rests against the primary interposer 202, thus blocking the path of the trigger reset arm 206 in lieu of this being done by the primary interposer 202.

As the pin 87 on the worm gear 52 completes its cycle it moves past the long tab 222 on the switch carrier 212 and the switch carrier then moves clockwise under pull of the tension spring 216. The lower sensor end 218 of trigger reset arm 206 comes to rest against either of the interposers 202 or 204. The small tab 224 of the switch carrier plate separates from the edge of the reset arm 206, with continued movement of the switch body 208 relative to the plunger 210, the latter being held by the tab 211 of the switch reset arm 206, and before the switch 208 and its carrier plate 212 reach their final position the switch plunger 210 is depressed by tab 211 relative to the switch body, thereby opening the electrical circuit and deenergizing the motor.

If the document remains inserted even after completion of the entire printing cycle, the forward stepped sensing edge of trigger reset arm 206 rests against the secondary interposer 204. When the document is finally withdrawn, the torsion spring 226 (FIG. 15) urges the primary interposer 202 against secondary interposer 204, and because of the greatly different lengths of the short and long arms of the torsion spring, the movement of the primary interposer 202 overcomes the resistance of the secondary interposer 204 and both interposers move to initial position.

The purpose of the step 230 (FIG. 17) at the lower end of reset ann 206 is so that the secondary interposer cannot follow the primary interposer when a document is first inserted. It lets the sensor 218 move safely into the path of the secondary interposer when the primary interposer is moved by the trigger. In normal rest position when step 230 bears against the primary interposer 202 the next higher part of reset arm 205 is already in the path of secondary interposer 204, as shown by the broken line position of the lower end 218 of reset arm 206, which is a little to the left of the solid line position. The step 230 serves the same purpose as the displacement in FIG. 7 between the steps 95 and 97, whereby interposer 90 in FIG. 7 cannot follow interposer 86, when the trigger is first moved back by an inserted sheet.

Because the operation is independent of gravity the device may be used in any convenient position. FIG. 19 shows it hung on a wall with its throat 14 upward. The document is slid downward. The device may be hung with its throat downward, but with tissue thin sheets it is easier to handle the sheet when the throat is upward as in FIG. 19. The bottom of the device is provided with bayonet type slots to facilitate wall hanging.

It is believed that the construction, operation and advantages of our improved time stamp will be apparent from the foregoing detailed description. A received letter or document is simply slid into the throat of the machine, thus contacting a sensitive trigger which starts a travel motor. This quickly elevates the impression roller and rolls it across the print wheel (and the name plate when one is used) whereupon the impression roller drops and the document is released for removal. The time and date to be printed may be checked through appropriate windows for readout. The clock motor is electrically driven, and if the AC supply is not interrupted, the time stamp requires attention only once a month for change of month and sometimes for adjustment of the date.

The timing mechanism is" designed for silent operation, there being no solenoid to operate the pawl, and it uses a progressive rolling action instead of an impact or hammer action. The device therefore is useable in executive and professional offices, hospitals, and the like. Although the entire unit is small in dimension, the character size printed is substantial, say 0.054 wide by 0.l-inch high. The fixed printing block for identification inscription is readily changeable, requiring only a screw driver. The trigger mechanism is sensitive enough to respond to a single sheet of onion skin paper.

It will be apparent that while we have shown and described our improved time and date stamp in a preferred form, changes may be made without departing from the scope of the invention.

We claim:

1. A time stamping device comprising a housing within which is a timing motor, a series of time print wheels arranged next to one another so as to serially extend in a given direction, an operative driving connection between said timing motor and said print wheels, a carriage mounted for travel from one print wheel to the next in said given direction from a first position to one side of a first print wheel to a second position to the other side of the last print wheel, an impression roller carried by said carriage, resilient means operative on said roller to urge it into successive engagement with said wheels as said carriage moves from said first to said second position, whereby successive parts of a document inserted between said roller and said wheels are pressed successively against said wheels by said roller, means operatively connected to said carriage to cause travel thereof from said first to said second position, and means operatively connected to said carriage to cause it to move away from said wheels and to withdraw said roller from said wheels after said carriage reaches said second position and then return said carriage to said first position, said housing having a slot into which a document to be printed upon is adapted to be inserted and actuatable trigger means in said housing operatively connected to said means for causing carriage travel and effective to actuate the latter upon being actuatably engaged by said document.

2. A time stamping device as defined in claim 1, having a travel motor with reduction gearing and linkage means connected between said gearing and said carriage and effective to cause travel of the carriage through a cycle of travel from said first to said second position and back, said gearing and linkage means constituting essentially the sole driving instrumentality for said impression roller carried by said carriage, whereby said cycle is accomplished without hammer and/or solenoid noise.

3. A time stamping device as claimed in 2, in which there are rails on which said carriage rides during its movement from first to second position, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated beyond said impression position and in advance of said second position to afford movement of the carriage away from the print wheels, and means mounting said rails on said housing and effective to permit return movement of the carriage back to said first position beneath the rails.

4. in a time stamping device as defined in claim 3 an electrical switch, operating means operativelyconnected between said trigger means and said switch and effective to close said switch when the trigger is engaged by said document to initiate the printing operation, latch means, connecting means between said latch means and said switch and effective to hold the switch closed, and means responsive to return movement of the carriage operatively connected to said latch and effective to release the latch to permit the switch to open and terminate the printing operation.

5. A time stamping device as defined in claim 4, in which a cam is drivenly connected to said timing motor, a cam follower is operatively connected to said cam and to a pawl and ratchet mechanism, the latter being operatively connected to said print wheels to turn. the same, and in which the cam configuration is such as to cause smooth acceleration and deceleration of the pawl movement, whereby the operation is relatively quiet.

6. A time stamping device as defined in claim 5, in which the impression roller and carriage move progressively from print wheel to print wheel in the direction of the axis of the print wheels in moving from said first to said second position, and in which there is an ink ribbon extending from a supply roll to a takeup roll in a direction transverse to the axis of the print wheels, said ribbon being as wide as the entire assembly of print wheels, said ribbon being disposed beneath the print wheels and above the document to be stamped, and said carriage and impression roller travelling beneath the document to be stamped.

7. A time stamping device as defined in claim 1, in which an electrical switch is closed by said trigger when the latter is engaged by said document to initiate the printing operation, latch means to hold the switch closed, and means responsive to return movement of the carriage to release the latch to permit the switch to open and terminate the printing operation.

8. A time stamping device as defined in claim 1, in which a cam is drivenly connected to said timing motor, a cam follower is operatively connected to said cam and to a pawl and ratchet mechanism, the latter being operatively connected to said print wheels to turn the same, and in which the cam configuration is such as to cause smooth acceleration and deceleration of the pawl movement, whereby the operation is relatively quiet.

9. A time stamping device as defined in claim 1, in which there are rails on which said carriage rides during its movement from said first to said second position, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated beyond said impression position and in advance of said second position to afford movement of the carriage away from the print wheels, and means mounting said rails on said housing and effective to permit return movement of the carriage back to said first position beneath the rails.

10. A time stamping device comprising a housing within which is a timing motor, a series of time print wheels and mechanism driven by said timing motor to turn said print wheels, a carriage mounted for travel along said print wheels in a printing stroke from a first position located to one side of a first print wheel and a second position located to the other side of the last print wheel, means operatively connected to said carriage for thus moving it and for returning it to said first position after a printing stroke, an impression roller carried by said carriage and serving to press against said print wheels successive parts of a document inserted between said roller and said wheels, said impression roller being spaced from said print wheels when said carriage is in said first position, said rails in said housing on which the carriage rides during its print travel, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated at said second position to afi'ord movement of the carriage away'from the print wheels, and

said carriage when said carriage is located on top of said rails, said starting end of said rails being movable upwardly, thereby to permit passage of said carriage there beneath in moving from said second position back to said first position. 

1. A time stamping device comprising a housing within which is a timing motor, a series of time print wheels arranged next to one another so as to serially extend in a given direction, an operative driving connection between said timing motor and said print wheels, a carriage mounted for travel from one print wheel to the next in said given direction from a first position to one side of a first print wheel to a second position to the other side of the last print wheel, an impression roller carried by said carriage, resilient means operative on said roller to urge it into successive engagement with said wheels as said carriage moves from said first position to an impression position to said second position, whereby successive parts of a document inserted between said roller and said wheels are pressed successively against said wheels by said roller, means operatively connected to said carriage to cause travel thereof from said first to said second position, and means operatively connected to said carriage to cause it to move away from said wheels and to withdraw said roller from said wheels after said carriage reaches said second position and then return said carriage to said first position, said housing having a slot into which a document to be printed upon is adapted to be inserted and actuatable trigger means in said housing operatively connected to said means for causing carriage travel and effective to actuate the latter upon being actuatably engaged by said document.
 2. A time stamping device as defined in claim 1, having a travel motor with reduction gearing and linkage means connected between said gearing and said carriage and effective to cause travel of the carriage through a cycle of travel from said first to said second position and back, said gearing and linkage means constituting essentially the sole driving instrumentality for said impression roller carried by said carriage, whereby said cycle is accomplished without hammer and/or solenoid noise.
 3. A time stamping device as claimed in claim 2, in which there are rails on which said carriage rides during its movement from first to second position, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated beyond said impression position and in advance of said second position to afford movement of the carriage away from the print wheels, and means mounting said rails on said housing and effective to permit return movement of the carriage back to said first position beneath the rails.
 4. In a time stamping device as defined in claim 3 an electrical switch, operating means operatively connected between said trigger means and said switch and effective to close said switch when the trigger is engaged by said document to initiate the printing operation, latch means, connecting means between said latch means and said switch and effective to hold the switch closed, and means responsive to return movement of the carriage operatively connected to said latch and effective to release the latch to permit the switch to open and terminate the printing operation.
 5. A time stamping device as defined in claim 4, in which a cam is drivenly connected to said timing motor, a cam follower is operatively connected to said cam and to a pawl and ratchet mechanism, the latter being operatively connected to said print wheels to turn the same, and in which the cam configuration is such as to cause smooth acceleration and deceleration of the pawl movement, whereby the operation is relatively quiet.
 6. A time stamping device as defined in claim 5, in which the impression roller and carriage move progressively from print wheel to print wheel in the direction of the axis of the print wheels in moving from said first to said second position, and in which there is an ink ribbon extending from a supply roll to a takeup roll in a direction transverse to the axis of the print wheels, said ribbon being as wide as the entire assembly of print wheels, said ribbon being disposed beneath the print wheels and above the document to be stamped, and said carriage and impression roller travelling beneath the document to be stamped.
 7. A time stamping device as defined in claim 1, in which an electrical switch is closed by said trigger when the latter is engaged by said document to initiate the printing operation, latch means to hold the switch closed, and means responsive to return movement of the carriage to release the latch to permit the switch to open and terminate the printing operation.
 8. A time stamping device as defined in claim 1, in which a cam is drivenly connected to said timing motor, a cam follower is operatively connected to said cam and to a pawl and ratchet mechanism, the latter being operatively connected to said print wheels to turn the same, and in which the cam configuration is such as to cause smooth acceleration and deceleration of the pawl movement, whereby the operation is relatively quiet.
 9. A time stamping device as defined in claim 1, in which there are rails on which said carriage rides during its movement from said first to said second position, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated beyond said impression position and in advance of said second position to afford movement of the carriage away from the print wheels, and means mounting said rails on said housing and effective to permit return movement of the carriage back to said first position beneath the rails.
 10. A time stamping device comprising a housing wiThin which is a timing motor, a series of time print wheels and mechanism driven by said timing motor to turn said print wheels, a carriage mounted for travel along said print wheels in a printing stroke from a first position located to one side of a first print wheel and a second position located to the other side of the last print wheel, means operatively connected to said carriage for thus moving it and for returning it to said first position after a printing stroke, an impression roller carried by said carriage and serving to press against said print wheels successive parts of a document inserted between said roller and said wheels, said impression roller being spaced from said print wheels when said carriage is in said first position, said rails in said housing on which the carriage rides during its print travel, the starting end of said rails sloping up toward said print wheels from said first position to lift the carriage and impression roller into operative engagement with said print wheels as the carriage is moved toward said second position, said rails being terminated at said second position to afford movement of the carriage away from the print wheels, and means mounting said rails on said housing and effective to permit return movement of the carriage back to said first position beneath the rails.
 11. The time stamping device of claim 10, in which there are means operatively connected to said rails to support them against downward movement thereby to support said rails and said carriage when said carriage is located on top of said rails, said starting end of said rails being movable upwardly, thereby to permit passage of said carriage there beneath in moving from said second position back to said first position. 